This invention relates to apparatus for the pyrolytic treatment of solid carbonizable materials, such as coal, shredded scrap-tires, comminuted municipal waste, sawdust and wood shavings, and the like, to convert same into valuable products including combustible gases, liquid hydrocarbons and solid carbonaceous residues. The treatment takes place in a cylindrical, horizontally-disposed vessel including a material conveying device which transports the carbonizable materials through the reactor vessel as a moving bed. A heating chamber is arranged coaxially around the reactor vessel.
The apparatus of this invention is an improvement on the pyrolysis apparatus disclosed and claimed in my earlier U.S. Pat. No. 4,123,332 entitled Process and Apparatus for Carbonizing a Comminuted Solid Carbonizable Material. According to the description in the aforementioned patent, solid carbonizable material is passed through a high-temperature, air-free reaction zone (defined by the reaction vessel) by paddle-like impellers mounted on a rotatable shaft which extends through the zone. The material passing through the reaction zone is subject to an indirect heat transfer relationship via a burning air-fuel mixture spirally swirling within the heating chamber which coaxially surrounds the reaction vessel. The burning air-fuel mixture travels in a direction generally counter-current to the material passing through the reaction zone and, after its substantially complete combustion, leaves the heating chamber via an exhaust gas exit conduit located at a low point in the heating zone. During its passage through the reaction zone the material to be carbonized is converted by pyrolysis, or high-temperature destructive distillation, into combustible gases, liquid hydrocarbons and solid carbonaceous residues.
The apparatus disclosed and claimed in my U.S. Pat. No. 4,123,332 is well suited for carrying out the pyrolysis of carbonizable materials and solid organic wastes containing hydrocarbons, particularly shredded scrap tires. It is important to the economics justifying the pyrolysis of scrap tires, and other organic materials, to obtain maximum heat transfer efficiency between the burning air-fuel mixture heating the reaction vessel wall and the material within the reaction vessel which is heated by heat conduction, convection and radiation. Also, fullest utilization of the heat value of the burning mixture within the heating chamber leads to improved apparatus and process heat balance efficiency.